You might remember this post where I asked about how sorting by “Hot” gives you a lot of new posts that were posted in quick succession, making it look like “New”.

I was recommend by a few to use “Scaled”, so recently I did. Except this felt even worse: I saw new posts that were posted in succession with 0 upvotes, one having 1 upvote.

Isn’t this weird? Or am I doing it wrong?

  • MHLoppy@fedia.io
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    11 days ago

    You’re making assumptions about how they work based on your intuition - luckily we don’t need to do much guesswork about how the sorts are actually implemented because we can just look at the code to check:

    CREATE FUNCTION r.scaled_rank (score numeric, published timestamp with time zone, interactions_month numeric)
        RETURNS double precision
        LANGUAGE sql
        IMMUTABLE PARALLEL SAFE
        -- Add 2 to avoid divide by zero errors
        -- Default for score = 1, active users = 1, and now, is (0.1728 / log(2 + 1)) = 0.3621
        -- There may need to be a scale factor multiplied to interactions_month, to make
        -- the log curve less pronounced. This can be tuned in the future.
        RETURN (
            r.hot_rank (score, published) / log(2 + interactions_month)
    );
    

    And since it relies on the hot_rank function:

    CREATE FUNCTION r.hot_rank (score numeric, published timestamp with time zone)
        RETURNS double precision
        LANGUAGE sql
        IMMUTABLE PARALLEL SAFE RETURN
        -- after a week, it will default to 0.
        CASE WHEN (
    now() - published) > '0 days'
            AND (
    now() - published) < '7 days' THEN
            -- Use greatest(2,score), so that the hot_rank will be positive and not ignored.
            log (
                greatest (2, score + 2)) / power (((EXTRACT(EPOCH FROM (now() - published)) / 3600) + 2), 1.8)
        ELSE
            -- if the post is from the future, set hot score to 0. otherwise you can game the post to
            -- always be on top even with only 1 vote by setting it to the future
            0.0
        END;
    

    So if there’s no further changes made elsewhere in the code (which may not be true!), it appears that hot has no negative weighting for votes <2 because it uses the max value out of 2 and score + 2 in its calculation. If correct, those posts you’re pointing out are essentially being ranked as if their voting score was 2, which I hope helps to explain things.


    edit: while looking for the function someone else beat me to it and it looks like possibly the hot_rank function I posted may or may not be the current version but hopefully you get the idea regardless!

    • .Donuts@lemmy.worldOP
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      11 days ago

      Thanks! That clears up a lot. Appreciate the paraphrasing too.

      You’re making assumptions about how they work based on your intuition

      Small difference: I made the assumption that the simplified version was exactly how it works, as in, taking the comment at face value.